Pathetic customer service

I have been a customer for 9 years with a average account of R1500+ per month. In January I called for an Upgrade on my 2nd contract where they advised me that I cannot upgrade my contract. I then requested how to go about cancelling this contract. 11 March I called to cancel where they stated I need to call in April. 12 April I called to cancel. I spoke to a consultant where she advised that the retentions department will be in contact to finalize the cancellation. As I have true caller on my phone, and retentions is marked as Spam, the calls were blocked. I then stopped paying the additional on the account in May 2023. Benefits were still loaded but as I don't use this number I was not aware. I called and emailed EVERY MONTH since the contract was due for cancellation. After numerous calls and discussions in July & Aug Cell C refuses to assist by writing off the amounts not paid as they say benefits was used. Eventhough the contract has now moved to month 26,27 and 28. According to law I only signed a contract for 24 months. After the discussions my primary number was suspended. Now I refuse to pay this account as I am being victimized and forced. the Primary number is due for Cancellation in September. My number has been totally shut down as I can not even receive calls any more. This is pathetic and I am disgusted by the way Cellc treats longstanding customers. I have received numerous calls from accounts where the staff has been so rude and tells me, "I just don't want to pay" That is not the case, I did send the required information in time but someone at cell C that did not do their work and now I am being held responsible,